Note: Descriptions are shown in the official language in which they were submitted.
~27~901
"LID FOR ACCUMULATORS, BLOCKED BY PRESSURE ON THE CONTAINER AND CONTAINER
SUITED TO RECEIVE SUCH LID".
The present invention refers to a lid for accumulators and to the con-
tainer suited to receive it.
It is known that the lids of electric accumulators are joined to their
tank or container in a permanent way and so as to insure a good tight-
ness between the lid and the container. The tightness is necessary bothbecause the leaking of the electrolyte during the operation of the accu-
mulator can only be avoided by a good tightness,and because only the
hermetical tightness garantees the good functioning of some automatic
re-filling systems of the Electrolyte.
For this reason, all the accumulators now found on the market have their
lids welded to the container either through the direct melting of the
plastic material or by gluing.
T;~e welding done both with the hot metal-plate system
and with the ultra-sound system forms a line of welding, which must be
trimmed with suitable devices.
Although the welding between the lid and the container is present prac-
tically on all the accumulators, said welding presents some relevant
disadvantages.
The most important disadvantage consists in the fact that the welded
lids can never be taken off again, unless the lid itself is destroyed
and the content is damaged.
Therefore, when the accumulator breaks down, for instance because of
a short circuit between the plates, an economical repair is not possi-
ble since, as it has been said, the access to the accumulator plates
entails the opening of the same by breaking open the lid.
Especially if reference is made to industrial accumulators, for instan-
ce to the ones used for traction, it can be noticed how advantageous
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it would be, if said accumulators, which are usually
rather costly, could be repaired.
On the other hand, it is not possible to resume the
use of accumulators having their lids sealed with
putty as was the case in the old constructions, since
that system is very costly.
Another inconvenience ensuing from the welding between
the lid and the container concerns the fact that the
welding operation itself and the subsequent, almost
unavoidable, trimming operation, are costly
operations, requiring special equipment.
It is a feature of one embodiment of the present
invention to overcome the just mentioned
inconveniences.
In particular, a feature of one embodiment of the
present invention obtains a lid suited to be joined
with accumulator containers in a stable way and with
good tightness, without making it necessary, for this
reason, to weld the lid and the container together.
Another feature of an embodiment of the present
invention provides that the lid may be blocked by
means of pressure on the container, so that it can
also be removed, if necessary, so that the access for
the eventual maintenance of the battery may be made
possible.
The above-mentioned features and others which will be
better explained hereafter, are obtained with the
construction of a lid made of plastic material, suited
to be coupled by simple pressure with accumulator
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containers, which, in accordance with the patent
claims, is characterized by the fact that it presents
a double perimetrical edge, in which at least one of
said edges presents at least one continuous projection
contrasting with the vertical walls of the container,
and in which said container presents a perimetric
external impression in bas-relief or an indentation on
which the cogs being present on the terminal part of
at least one edge of the lid get caught.
In accordance with an embodiment of the present
invention there is provided a lid for accumulator
containers, made of plastic material and suited to be
fixed on containers presenting at least a perimetric
external impression in bas-relief, characterized by
the fact that it presents two perimetric edges, each
of them going to contrast against the vertical walls
of the container, and in which at least one of the
edges presents a projection forming a continuous cord
tightening on the container and a cog hooking the
impression of the container, the cog not being
necessarily present on the edge itself.
In accordance with another embodiment of the present
invention there is provided a container for
accumulators, made of plastic material and obtained by
the blow-moulding process, suited to be coupled with
the lid described in the preceding paragraph,
characterized by the fact that it presents at its
upper edge an indentation or a perimetric impression
with an indentation, each of them being suited to
block at least one cog belonging to one of the two lid
edges.
Other characteristics and advantages will be better
understood from the description of a preferred form of
execution of the lid being the ob-
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ject of the invention, which is given in the way of example only, but
which is not meant to limit the scope of the invention, and which is
illustrated in the enclosed tables of drawing, where:
- Fig. 1 shows a partial cross-section of the lid of the invention.
5- - Fig. 2-shows a cross-section of the edge of the accumulator container
reGeiving the lid of Fig. 1.
- Fig. 3 shows a cross-section of the lid and the container being coupled.
- Fig. 4 shows a cross-section of a variation of the lid of Fig. 1 with
the respective suitable container
- Fig. 5 shows a view of an accumulator with the lid of the invention.
With reference to the mentioned drawings, in Fig. 2 a cross-section
of the profile of an accumulator container 1 can be observed. This
container, made of plastic material,is of the type which is obtained by
blow-moulding
As it is known and as it has been described in the app'ication for the
European patent No. EP-0082826, with the blow-moulding process it is
possible to obtain containers presenting even indented channel-shaped
impressions along the perimeter, as can be observed in the cross-sec-
tion of Fig. 2 and as it is also visible in the perspective view of
Fig. 5. More specifically, the indented impression 2, which is pre-
sent near the upper edge of container 1, and the vertical surface 3
inside the container being formed by indentation 2, are meant, in the
case under examination, for the anchorage of lid 4, as will be explain-
ed later on.
In fact, lid 4, also being preferably made of plastic material, pre-
sents two edges, 5 and 6, having vertical profiles differring from
each other, butwith characteristics in common. In both edges, in fact,
there are two projections 7 and 9 in relief on the vertical surface and
turned in such a direction, so that they will be in contrast with the
wall of container 1.
More precisely, the inside edge 5 of lid 1 presents a projection 7 having
a practically semi-circular section and a cog 8 at the lower end of
the edge. Thus the outside edge also presents a projection 9 having
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a practical1y semi-circular section and a cog 10 on the lower end of
the edge.
When the lid is closed by pressure against the edge of container 1, the
elasticity of the material and the shape of the lid edges allow
the edges 5 and 6 to open, so as to leave the space necessary for the
insertion of the edge of container 1. When the lid is inserted along
the entire perimetrical edge, the areas of tightness between the lid
and the container are at least three, namely, the entire rim 7 of the
the internal edge of the lid which presses on the inside surface 3 of
the container, the entire rim 9 of the external edge of the lid, which
presses against the external surface 11 of the container,and the flat
area 12 of the container being comprised between the edges 5 and 6,
which engages edge 13 of the container.
Since the distance between projection 7 and projection 9 of the
lid, when the lid is separated from the container, is shorter than the
distance between the two surfaces 3 and 11 of the container, it can be
understood that, when the lid is placed on the container, the projections
7 and 9 exert pressure against the walls 3 and 11 of the container, thus
insuring the tightness.
20- Experimentally it has been noticed that a good degree of tightness be-
tween the lid and the container is reached when the minus difference
between the distance of the projections 7 and 9, on one hand, and of
the surfaces 3 and 11, on the other, is of about 1.5 mm.. The cogs 8
and 10 of the lid, as can be seen in the cross-section of Fig. 3, are
left free, but respectively inserted in the impressions 15 and 2 of
the container. Thus, during the aging process of the accumulator, when
the poles tend to lengthen and the lid receives a push upwards,which
is partly absorbed by the deformability of the lid surface, the cogs 8
and 10 prevent the opening between the lid and the container.
When, on the other hand, the accumulator needs to be re-opened, for in-
stance, in order to perform the repair of a short-circuited plate, this
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can be done by acting on the elastic deformation of the outside
wall 6 of the edge. In fact, cog 8 is able to go over the rim 16,
since this is sufficiently radiused.
A variation concerning the lid of the invention is represented in
Fig. 4, where lid 20 also presents two perimetric edges 21 and 22,
but, in this case, there is only one projection 23, being present
on the wall of the external edge 21, which contrasts with the inden-
ted edge 24 of container 25.
Besides, on the lid there is only one cog 26 which resists the
releasing tension of the lid.
In the case under examination, container 25 presents a simplified
shape with a single perimetric indentation 24 along its edge. This
indentation is dimensioned so that the shape of the external edge 21
of lid 20 does not protrude in relation to the vertical wall of con-
tainer 25.
The tightness between lid 20 and container 25, in this case, is in-
sured by the perimetric rim 23, by the flat edge 27 of the container,
which is in contact with lid 20, and by the contact between the vertic-
al surfaces of the inside edge 22 and of the indentation 24 of the
container.
It is important to point out that,in each of the two given examples,
the external edge of the lid never protrudes in relation to the ver-
tical walls of the container. Thus it is possible to build an accu-
mulator battery without losing any space between an accumulator and
25. the next one.
From the description of the examples of the forms of execution given
above, it can be seen that with the lid of the invention, the tight-
ness between the lid and the container is obtained without any need
for welidng, in order to obtain it. Moreover, the lid can be removed
-in case of break down of the accumulator by using its elasticity and
without breaking neither the lid nor the container.
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It will be possib1e to introduce variations, either in the construction
or the form of the present invention. For instance, the form or the
number or the position of the projections 7 and 9 of the two edges,
as well as the shape and the position of the cogs 8 and 10, or the
shape of the container impression receiving the lid may be varied.
All this can be done without exceeding the scope of the invention, as
it is described in the following claims.
